[Click] Userlevel versus Linuxmodule

[Italo Valcy]

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Hi guys,

Em 20-08-2010 04:51, Beyers Cronje escreveu:
> 
> By default in userlevel using FromDevice the kernel will also process the
> packets. However there is a workaround using the following FromDevice config
> parameter:
> 
> *SNIFFER*Boolean. Specifies whether
> FromDevice<http://read.cs.ucla.edu/click/elements/fromdevice> should
> run in sniffer mode. In non-sniffer mode,
> FromDevice<http://read.cs.ucla.edu/click/elements/fromdevice>
>  installs KernelFilter
> <http://read.cs.ucla.edu/click/elements/kernelfilter> filtering
> rules to block the kernel from handling any packets arriving on device
> DEVNAME. Default is true (sniffer mode).
> 
> So setting SNIFFER to false will block the kernel from handling packets as
> well.

Just another question: this workaround seens to use iptables to block
kernel from handling the packages, but do I have some way to give back
the package to the ordinary Linux protocol stack? In other words, is
there any workaround to have the same behavior of ToHost in linuxmode?

I'm asking these questions because I'd like to be able to use
test-ping.click example [1] in userlevel. Can I do this or should I
start thinking about to use linuxmode instead of userlevel?

Thanks for any help!


Kind Regards, italo.

1 - test-ping.click example
- ---------------8<----------------------
// test-ping.click

// This kernel configuration tests the FromDevice and ToDevice elements
// by sending pings to host 131.179.80.139 (read.cs.ucla.edu) via 'eth0'.
// Change the 'define' statement to use another device or address, or run
// e.g. "click-install test-ping.click DEV=eth1" to change a parameter
at the
// command line.
//
// You should see, in 'dmesg' or /var/log/messages, a sequence of "icmp
echo"
// printouts intermixed with "ping :: ICMPPingSource" receive reports.  Also
// check out the contents of /click/ping/summary.

define($DEV eth0, $DADDR 131.179.80.139, $GW 131.179.33.1)

FromDevice($DEV)
	-> c :: Classifier(12/0800, 12/0806 20/0002, -)
	-> CheckIPHeader(14)
	-> ip :: IPClassifier(icmp echo-reply, -)
	-> ping :: ICMPPingSource($DEV, $DADDR)
	-> SetIPAddress($GW)
	-> arpq :: ARPQuerier($DEV)
	-> IPPrint
	-> q :: Queue
	-> { input -> t :: PullTee -> output; t [1] -> ToHostSniffers($DEV) }
	-> ToDevice($DEV);
arpq[1]	-> q;
c[1]	-> t :: Tee
	-> [1] arpq;
t[1]	-> host :: ToHost;
c[2]	-> host;
ip[1]	-> host;
- ---------------8<----------------------


- -- 
Saudações,

Italo Valcy :: http://wiki.dcc.ufba.br/~ItaloValcy
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